


In Too Deep

by MegaFrost4



Category: Doctor Who (2005), Sherlock (TV), Supernatural
Genre: Bad Wolf Bay, Episode AU: s02e13 Doomsday, Episode: s02e13 Doomsday, F/M, M/M, Multiple Crossovers, Season Finale
Language: English
Status: Completed
Published: 2020-12-16
Updated: 2020-12-16
Packaged: 2021-03-10 19:20:53
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,921
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28102326
Author URL: https://archiveofourown.org/users/MegaFrost4/pseuds/MegaFrost4
Summary: SUPERWHOLOCK Doomsday!AU The Daleks and the Cybermen declare war, and the Doctor and his companions fight to defend the Earth. But, not everything goes according to plan...
Relationships: Castiel/Dean Winchester, Sherlock Holmes/John Watson, Tenth Doctor/Rose Tyler
Comments: 1
Kudos: 5





	In Too Deep

"Settle down, girls." John Watson raised his eyebrows at the Doctor, Dean Winchester, and Sherlock Holmes, who had previously been yelling at each other.

Rose Tyler giggled, then looked at Castiel, who just met her with that confused puppy look.

"Just an expression." Rose clarified.

"It's very difficult to decipher amongst humans...and Time Lord, what phrases should be taken as they are perceived, and ones that should be taken metaphorically. Sarcasm is amusing, though."

"You'll get the hang of it." Rose placed an assuring hand on Cas' shoulder.

John walked up to them, huffing. "Honestly, they are as hard-headed as they come."

"That's why we're always together." Rose smiled.

"Right, still no sign of anything, Castiel?"

"Haven't heard any disturbances on our floor yet, but they are on their way."

"We need to hurry." Rose walked back to the Genesis Ark, careful not to touch it.

"We can't just stay here like bait!" Dean yells.

"What do you propose we do with no amo?!" Sherlock growls.

"No, we're not using guns! Someone could get hurt." The Doctor cuts his eyes to Rose.

"Hate to break it to ya, Doc, but those Cyber-douchebags and Dafucks aren't going to take it easy on us cause we don't have squat!"

"Dean, stop!" Cas grabs his attention. "Arguing won't help us at all."

Dean looks at Cas, and just rolls his eyes, calming down a little. "Good thing you're cute." He squeezes Cas's shoulder then walks off.

"C'mon Sherlock, isn't there anything we can do?" John looked eagerly at Sherlock.

Sherlock looked back at the Ark, his brain going over every detail. Time-travelers were the only ones that could set it off and unleash a hell of Daleks into the world with just their touch. That included all of them. But then again, the Void between universes is the best solution to get rid of the Ark, the remaining four Daleks, and all of those Cybermen wreaking havoc outside. The screams echoed in his Mind Palace, people being upgraded...exterminated.

This war had to be stopped.

But how?

"Is he in his head again?" Cas asked John.

John nodded. "Yes, hopefully getting close."

"Doctor..."

The Doctor looked at Rose and smiled.

"Can we pull this off?" She asked hopefully.

He saw that fire he fell in love with. The sheer determination. He looked at his other companions, his friends, and smiled. They were each so special and brilliant in their own unique ways. He would not trade them for the universe.

"Oooh, yes, Rose Tyler!" His smile grew to his ears. "We can do _anything_."

"Except shoot these sons of bitches..." Dean mumbled.

"Dean, you and I both know guns aren't going to kill these things."

"Are you saying we can't kill them?" Dean was appalled.

"I'm saying we don't have to." Sherlock interrupted, a crazed look in his eye he always has right after emerging from his Mind Palace.

* * *

"Sherlock Holmes, you brilliant man!" The Doctor enthusiastically hugged Sherlock, who shyly hugged him back.

John smirked. After all this time being around a Time Lord, an angel, and an American, he was still not an intimate person.

"Go on, Cas. I know you'll be..." Dean looked down at a gun he were suddenly holding that could have been pulled out of a Halo game. "...quick."

"How is that supposed to kill a Cyberman?" John looked doubtful, knowing his pistol would not make a dent.

"Oh! I'm surrounded by geniuses!" The Doctor high-fived Cas. Cas looked at Dean proudly. He had struggled with that gesture for a long time.

"Way to go, tiger." Dean smiled.

"Well, Doctor? We don't have much time." The rather annoying march up the stairs was getting louder and louder.

"Gold can weaken them enough that this bazooka should work."

"Dibs!"

Everyone looked at Dean.

"What? I've always wanted to try one of these bad boys." He picked it up and hoisted it on his shoulder. He tilted his head to the side, a manic smile on his face. " _Why so serious?_ "

" _What the hell_?" John looked so done with Dean.

Cas explained. "We watched The Dark Knight last night. Dean really got into it."

"Seen it 16 times." He bragged.

Cas added nonchalantly. "He thinks he's Batman."

"Oh, for God's sake." Sherlock walked over to the wall, preparing himself.

"Allons-y!" The Doctor grabbed Rose's hand and ran to the wall. Everyone else joined, hiding behind boxes and old desks.

Dean stood in front of the Ark, ready to shoot.

_**BOOM!** _

He looked over to Cas, who nodded confidently.

_**BOOM!** _

He focused his eye on the door, already beat in.

**_BOOM!_ **

He took a deep breath.

_**BOOM!** _

The metal door landed. Dean could only see three Cybermen, but he knew there were more.

"You must be upgraded." The first one said.

Dean laughed. "No thanks, I'm too adorable!"

"Then if you resist upgrading you must be deleted."

" _Dean._ " Cas did not understand why sassing was necessary right now.

"Hasta la vista, bitches-" **_BOOM!_**

It all happened so fast.

"Dean! C'mon!" Cas grabbed Dean and appeared at the wall with the others.

Dean could not hear for a second and looked at the Ark. A spot of blood dripped to the floor.

" _Oh shit_."

"Dean, what's wrong?" Cas whispered.

Dean looked at the others, the dread on their faces. "I touched it."

Sherlock closed his eyes, feeling the urge to punch him.

"Guys, its OK! We can-" Rose tried to stay positive.

"THE GENESIS ARK HAS BEEN ACTIVATED!" Daleks flew in, well, _that_ was new, and carried it through a hole where a door used to be on the roof.

"Nononononononono!" The Doctor bolted after them, the rest following suit.

"LONG LIVE THE DALEKS!" The Daleks all repeated, as the Ark floated into the sky. Opening up, the Genesis Ark released too many Daleks to count. Cybermen on the ground started shooting at their flying enemies.

"Doctor, what is it?" Rose asked him.

He did not answer at first, his mind racing. "Sherlock, I need you to crack a code for me."

Sherlock did not ask, but just smirked. "At your service."

Cas beams them all to a room with a computer, still functioning, surprisingly. The Doctor goes to it and Sherlock sits down, squinting his eyes.

"Put all of the coordinates at _six_." As if reading his mind, Sherlock continues working the system.

"Levers operational."

"OK, now. As soon as it opens, its going to be a bit rough, so everyone just hang on tight to these." He gestured to three handlebars that looked more like weights. He heaves one up and seals it to the wall. The other two are attached on the opposite wall. "Once we hit the red button, it'll be ready."

"I think I can manage." Dean waited until the Doctor gave him the thumbs up and then he hit it.

"Now, let's pull these levers back!" John and Sherlock did so, a white light appearing behind them.

"Everybody hold on!"

Winds billowing like a hurricane swept past them. Rose and the Doctor held onto one, Dean and Cas on the other across from them, followed by John and Sherlock on the third. They were all horizontal, not letting go.

An explosion grabs their attention, causing one of the levers to shift back off.

"I've got it!" Dean was determined not to screw up this time.

"Don't go anywhere, now!" John jokes as he grabs Dean's jacket.

The winds die down a bit, enough to make everyone less strained.

"C'mon, you son of a bitch!" John lets go of the handle that Sherlock was on and helps Dean pull it back.

" _Online and locked_."

"John!" Sherlock yelled. John turns to go back, but the winds pick up again, much more like a black hole, sucking everything in. John reaches for Sherlock as Dean looks at Cas.

"DEAN!"

"You stay right there, Cas! Don't-" A desk hits Dean in the shoulder, knocking him off and sending him flying."

John loses his balances, unable to grab ahold of Sherlock.

"JOHN!"

"Rose? Hang on!"

Rose grunts, her arms too tired.

"I'm slipping!"

"No! Don't let go!"

"Aaaahh!"

The Doctor grabs her hand, but the sweat caused her to slip right through his fingers.

"ROSE!"

A bright light envelops Dean, John, and Rose.

Then the rift closes.

The Doctor is panting, eyes wide.

Sherlock blinks rapidly, as if they were all there.

Cas lets a tear fall.

Sherlock looks at Cas, extremely annoyed. "Well, don't just _stand there_ like you lost your puppy, _go get them!_ "

Cas looks at him, face sunken in sorrow. "I...they are-"

"I don't _care_ if they're in another world, bring them back _now!_ "

"The rift is closed, that universe is sealed off. I can't." Cas choked, closing his eyes for a second. "Not even the Doctor can do anything now."

They both looked at him. He placed his hand longingly on the wall, leaning in ever so slowly to press his ear to listen.

Cas growled, trying to appear over there, but kept bouncing back literally. After falling down a third time, he sobbed.

Sherlock slammed into the wall then wrung his fingers through his thick, black curls, trying but failing to figure out a way. There has to be.

One by one, they follow the Doctor to the TARDIS. Once all inside, she disappears.

* * *

"What the hell?!" Dean sits up and sees John storming around what looks like the same room in reverse, only there are three people missing.

"Take me back! Take me back!" Rose sobbed, banging on the wall. "No..." She stiffens then turns her head, as if she could hear them.

"John! What do we do?" Dean has tears in his eyes.

John sniffs, looking back at the wall. "I don't know..."

Dean turns around, then kicks some rubble. "This is all my fault!"

"Now, wait just a minute!" John pointed at him.

"No?! Well, then, how about _me_ opening the Ark? That was _not_ part of the plan! I released all of those fucking terminators out into our world! I DID THAT! And then I wasn't strong enough..."

"The lever was jammed!"

"It should've just been me! I should be the one punished! Not you and Rose too!"

"Dean, I was just trying to help. I am devastated. Sherlock means the world to me, and right now, we need to take a minute and settle down so we can figure out what we're going to do."

John walked over to Rose, and helped her up, then hugged her.

"We'll do them no good here." John walks Rose over to Dean. "I've got enough cash for some takeout and we can crash at my place till we can wrap our heads around this."

"If it's even in this ass-backwards universe."

John gave Dean a like look.

"Dinner's on me."

Rose took Dean's hand, her eyes red from tears, then pulled him into a hug.

They all looked one last time at the blank wall, as if waiting for their other halves to burst through. But that moment never came. Together they left the building, John called a taxi, and they were off.

The ride was silent, all three squished in the back with Rose in the middle.

"Baker Street." John's voice hitched slightly, as the cabbie acknowledged cheerfully.

It was only twenty minutes later when they arrived. John prayed silently that it existed in this world. He paid the cabbie, and they all piled out. John looked around in the dark, then saw Speedy's, and sighed in relief.

Finally some good news.

But when they approached the door, 221B had an eviction notice, and John panicked.

"Oh my God..." He pulled out his key and fumbled his shaky hands, but it did not work.

"Here, let me get it." Dean reached into his pocket and picked the lock, opening it for John and Rose.

"I'm gonna hit Speedy's real quick." He smiled at the joke, the others smiling with him, to his shock.

John led Rose upstairs, a pit in his stomach. What happened here? Did it really happen?

They went inside to find everything as he had remembered. The skull on the mantle, a clean kitchen.

Wait, _clean?!_

John's stomach flipped. He remembered. This happened when...

A newspaper caught his eye. He had to know.

"John?" Rose was concerned. Maybe they should have gone to a motel.

**SPLAT! Guy Who Wore That Hat in That Photo: Totally Dead**

John felt his leg give out, slumping into his chair, and dropping the article.

"Oh John." Rose knelt down in front of him, taking one of his hands from his face. "Hey, look at me. This is not our world. Whatever happened here doesn't matter. You know he's still alive...back home."

"I know, I know, it's just..." He bit his lip hard. "I had cleaned up the place before I left, because I...gave up on him."

"John, listen to me. You didn't know. I mean, for all we know, he could have faked his death here too, and became a professor at Cambridge...I'm a dog here."

John looked at her, then laughed. Perhaps Sherlock really is alive and well here.

" _John? Rose?_ "

"Up here, Dean!" John called.

Dean entered with three clubs and some drinks. "Guess what?" He pulled out a box. "I got the last pie!"

They all laughed and began eating, only just now registering how hungry they were.

As Dean scraped the last bit of pie up to his mouth, John leaned forward in his chair. He looked at the two on the couch.

"We are going back. Not sure how, but I bet with those three...we can all find a way."

"If those smart asses can agree on how to change a lightbulb." Dean jeered.

They all laughed. Their significant others always think they're right. It was always a battle of the wits.

"I believe in them." Rose smiled. They all nodded.

"Well, let's get some rest, you two can have the bedrooms..."

"But, John, your leg." Rose began to protest.

"You all know very well it keeps me up. It'd be no good for me to waste a bed. Now, go on."

Rose wanted to disagree, but she was tired, so she got up, kissed each of them on the cheek, and went to Sherlock's bedroom.

"Need anything, just holler. I'm a light sleeper." Dean took off his coat as he went to John's room.

John sighed, knowing exactly what Dean meant by "light sleeper." Nightmares plagued him over losing his brother. It has only been a little over a year since Sam had fallen into the pit, and images of that day haunted Dean. John feared his nightmares would haunt him as well, now that he is reliving his worst nightmare.

But Sherlock is not dead. He was just very far away.

* * *

"There just has to be!" Sherlock threw a book across the library in the TARDIS.

Cas looked at the two, his powers weakened. Trying to cross over beat him up pretty bad.

"If there was, I would've already told you!" The Doctor yelled back.

Sherlock stormed off, slamming the door on his way out.

"I know you're trying. He just really misses him. And you miss her." Cas encouraged.

"And you miss Dean."

Cas teared up. The Doctor exhaled, taking off his glasses. "Look, I cannot even figure out how they got over there in the first place. They should've..."

"I know. This could be because of Him-"

"Castiel, I have searched longer than you have. There is no sign of Him anywhere. It, just doesn't make sense."

"That's what a lot of my brothers and sisters used to say. He's as mysterious as they come."

" _Doctor! Castiel!_ " Sherlock called.

Could this be it?

Sherlock was reading the screen at the TARDIS' control center, mumbling to himself.

He pointed to the screen. "Doctor, is this possible if we-"

"Let me see." Putting his glasses back on, the Doctor read through the calculations, and saw a small hole. "Well..."

"What?" Cas stepped forward.

"Oh no..." Tears welled up.

" _What?_ " Sherlock asked.

"It's not enough." The Doctor said, dejected.

"What do you mean?" Sherlock wrinkled his forehead.

"There's a single, tiny gap in the universe..."

"Can she squeeze through?" Sherlock looked a little hopeful.

"No, but part of us can." They stared at him, so he continued. "There's a supernova, and that is only enough power to send projections of us over there for a limited amount of time."

"So we can't bring them back with these projections?" Cas thought.

"If we come into contact with anything...or anyone over there, both universes collapse."

Silence.

"And that's all we can do? Just look at them?!" Sherlock's temper was rising. "All of that power, and it's _still_ not enough?!"

"We didn't get to say goodbye." Cas pointed out solemnly. "Now's our chance to see them...one more time..."

Sherlock pouted, not convinced there was no more they could do, but sighs, defeated. "Fine. What are we going to do? And how are they going to find us on this short amount of time?"

"Leave that to me." Cas said.

* * *

Nightmares plagued them all for days. No one could sleep.

John got up and went to make some tea for them. "It calms the nerves," he would tell them.

Dean would rather just pass out from liquor, but Rose would have none of that.

"We need to stay focused. I can't have you kill yourself when they're still out there! I know they're not giving up on us. Don't give up on them."

They never brought up their nightmares of Hell, Reichenbach, Bad Wolf, whatever happened a week ago. They had all lost someone.

"Yeah, well...Sammy could've found the answer a long time ago before I could even make it to page two!" He started crying. He missed his brother, and still blamed himself.

They did not say anything. Rose just crawled over to his side of the couch and held him.

He cried himself to sleep.

Rose and John dozed off after the fact a little after three in the morning.

* * *

_Dean_

Dean twitched, waking Rose up.

"Are you alright?"

_Dean_

John blinked. "Rose?"

"I think he's having another nightmare."

_Dean_

Dean sat up abruptly, causing Rose to jump back.

"Dean?" He looked at John, then tried to steady his breathing as Rose rubbed his back soothingly.

"I know where they'll be."

They all threw their shoes on and ran out the door. Dean quickly put the coordinates and exact time into his phone before he forgot. They were coming: Sherlock, the Doctor, and Cas were coming.

John had grabbed some hidden money for the long drive ahead. Dean explained what had happened along the way via text, since they did not want to spend their time explaining to the cabbie their predicament. It was just a family emergency.

That they can hopefully fix...

They made it to the airport, and with one of Dean's credit cards, they were booked on the next flight to Norway. Their anxiety kept them from sleeping, so they went to a coffee shop. They could sleep on the plane.

Neither of them could.

When they arrived, Dean pulled out his phone and pulled up the coordinates and showed the driver.

"Little chilly this time of year?"

"Just drive." Dean snapped.

It was late morning by the time they arrived.

_Dean_

They ran to the beach, just thinking maybe...

The waves crashed the shore. They made it almost to the water's edge and stopped.

That was when they heard their names.

"Cas?" Dean walked forward.

"Doctor!" Rose just knew they could find them.

"Sher-" John stopped, seeing the hurt look. "What's wrong?"

"Where are you, really?" Dean asked.

Rose's shoulders slumped a little.

"Inside the TARDIS." The Doctor answered. "There's one tiny little gap in the universe left, just about to close. And it takes a lot of power to send this projection. We're orbiting around a supernova, burning up a sun...just to say goodbye..."

"You can't..."

"I wish there was a way, John. I haven't given up yet." Sherlock cut his eyes at the Doctor.

"Cas?"

"I've tried Dean. Countless number of times, and it's..."

"You look hurt." Realization hit Dean. "Cas, _stop_ before you kill yourself."

"Dean, I need you."

"Dammit, Cas, I prayed to you every night. You promised!" Dean composed himself. "But it's killing you, I need you to stop. Don't make me lose you forever."

"I'll find a way." The angel promised.

"Doctor, you all look like ghosts." Rose looked between them all.

"Hold on..." He takes his sonic screwdriver out, then they all appear solid.

"Sherlock?" John reaches out, but Sherlock shakes his head, tears threatening to fall.

"We're still just images. No contact."

John looked down, shutting his eyes.

"Can't we just squeeze through that tiny little gap? One at a time?" Dean begs.

"Dean, both universes will collapse."

"So?" Dean really does _not_ care at this point. Cas just smiles at him.

"John, where did the gap appear?" Sherlock asked.

"We're in Norway, 'bout fifty miles out of Bergen."

Rose raised an eyebrow. "It's called Darlig Ulv Stranden."

Cas' eyes widened.

The Doctor thought for a second. "Dalek?" Everyone chuckled.

"It's Bad Wolf Bay." Rose winks at the Doctor.

"How long have we got?" Dean asks, not wanting Cas to leave.

"About two minutes."

"That's it? All that-" Dean stops, not wanting Cas to remember him yelling at him.

"There's a Torchwood here. I think I know a thing or two about aliens." Rose smirked.

The Doctor smiled. "Rose Tyler, Defender of the Earth."

"John...there's something I should say, I've meant to always, and I never have."

John sucked in a breath.

"You tell me nonstop and-" Dean starts.

"Does it need saying?" Cas asked.

"Dammit, yes." Dean let the tears fall. "I love you, Cas. I love you."

Rose choked for a second. "I love you..."

The Doctor smiled. "Quite right, too."

"Oh, John, I-" Sherlock vanished.

"Rose Tyler-" The Doctor vanished.

"Dean-" Cas vanished.

They all stare at nothing for a moment, not able to comprehend what happened.

Rose covers her face and cries.

John cannot fight the tears anymore.

"CAAAAAAAAAAS!" Dean shouts, falling to his knees.

* * *

"Find another one." Sherlock quickly commands. No one answers for two whole seconds. " _Find another one!_ "

The Doctor just stares at the TARDIS, mouth hung open. It was at the tip of his tongue, and he choked it back.

Cas looked distraught. "Dean?" He vanishes, then comes back shaking his head. " _Dean?_ " He gets shot back again. "De-"

"Stop it! You're no good to him _dead_!" Sherlock lets go of Cas' trenchcoat slowly. He notices the blood drip from his nose.

The Doctor ignores them, too heartbroken to move.

* * *

"Cas, _please!_ " Dean begs. He cannot figure out if it was for him to try to come through or to stop hurting himself.

John stood like a statue, tears being the only thing in motion. He was going to say it. John knew Sherlock loved him, he just never verbalized it like John did.

Rose could not bear to look where he stood in front of her. She could feel her heart breaking.

 _Why_ did this happen?

What seemed like hours later, they left the beach, sick but more sure of themselves than ever before. They were going back home, whatever it takes.

* * *

The TARDIS moaned in despair.

**Author's Note:**

> I know, I know, it hurts me so much because I combined all the sad feels! I wanted to do this based on this SUPERWHOLOCK post I found on Pinterest here: https://www.pinterest.com/pin/548242954618285668/


End file.
